This invention relates to the printing of thin sheet lenticular lens materials, and more particularly, to a registration system for aligning a web of lenticular material on which images are printed with print rolls of a printing press so to adjust the lens material and printing plates for printing various of the colors used to print the images on the material. The registration system allows these adjustments to be made dynamically during an actual print run.
In co-pending U.S. patent application Ser. No. 082,715/09, there is described a method for printing images on thin sheet lenticular materials. A key feature of this method is the alignment of the color negatives, or plates made from the negatives, both to each other and to the lens material on which the images are printed. An alignment system is employed by which the registry of the colors are checked against a reference color so the plates can be adjusted orthogonally, laterally, and rotationally as need be. While the alignment described therein works well for its intended purpose, use of the system necessitates that a few images be printed on the flat side of the lenticular material, the color registration be checked using the system, adjustments to the plates alignments be made, if necessary, and additional images be printed to verify that the revised alignment indeed corrects whatever minor misalignments there may have been.
Most printing presses, and particularly those used for volume printing, have some type of system, usually hydraulic, by which the print rolls can be adjusted while a job is being run. The hydraulic or other control system permits minor adjustments in the rolls up and done, back and forth, and in and out. As described in the co-pending application, the thinness of the material and the number of lenticules per inch (LPI) of the material means that there is almost no margin for error in alignment in order to provide a quality lenticular product. It will be appreciated that despite the care and precision with which the process described in the copending application is carried out, that once a print run begins, changes may still occur which effect the registration. If the run must be stopped to make necessary adjustments, this creates delays and adds to the cost of the job.